1. Field of the Invention
The present invention relates, generally, to the fields of hydro power energy conversion from moving waters, including various wave energy converters, hydro turbines situated in rivers, lakes and tidal flows. In particular, the invention relates to water wheel types of devices.
2. Background Information
A vast source of potential energy is not presently being captured from the thousands of flowing streams, tidal currents, tidal streams and ocean and lake waves. In antiquity, water wheels were devised and used as grist mills and as water pumping machines. Yet today, water wheels are utilized in many countries in addition to hydro turbines. Historically, it has been difficult to obtain useable energy from slow-moving waters, with water falls and constructed dams being the source of hydro energy through capture of the potential energy of the water head. In this instance, the use of hydro turbines is employed. Hydro turbines are somewhat efficient, but they have the disadvantage of being expensive and require considerable maintenance for continued use. In addition, hydro turbines can be destructive of fish and aquatic life, as well as sensitive to floating debris. Such turbines also are limited in degree of energy conversion by their fluid entrance chamber.
Many suggestions as to various methods of capture of energy from flowing waters have been made through the years, including complicated, complex networks of coffer dams, concentrating valves, storage basins and underwater hydro planes, with reversible blades. In the majority of these propositions, the cost factor is limiting, and the effect of storms and floods reduces the practicality of their application. In addition to these, a system of utilization of Pelton wheels has been patented, which define buckets attached to a rotating wheel. The buckets have flowing waters confined in such manner that they form a water jet impinging upon or into the buckets.
The historic method of capture and conversion of flowing, cascading and waterfall water energy conversion is the employment of water wheels, of which there are four major types or styles. The most historical and familiar to us is the under shot water wheel, which is a vertical structure secured on a central axis with attached paddles or scoops. In like manner is the overshot water wheel that is caused to rotate via the flow of waters from an elevation, such as water falls, flumes or pipes conveying water from a distance, and which water is at a higher elevation. This same device can be utilized as a cross flow water wheel.
In all of the water wheel systems proposed to date, water flow is captured via paddles or blades that are attached to a wheel of considerable height for efficiency, with the paddles or blades positioned in close proximity to each other. Kinetic energy is wasted when one blade is located immediately or in close proximity behind another, since little or no water flow reaches the rearward blade and power is lost in dragging the rearward blade through and up and out of the water, which arrangement causes “slushing” of the waters against the axel or support shaft and its attached following blade. The waters from the forward flow blade impede the efficiency of the following blade and those that follow as they traverse in the same path way.
The for-runner of a great number of under shot water wheels is illustrated in U.S. Pat. No. 4,517 by C. Hand, issued May 16, 1846. In this patent, an attempt is made to have flow engaged paddles active on the up flow side of the waters and then to flow into the housing on the down side of the device, with the intent of allowing a free exit of fluid from the blades for efficiency. The difficulty of this system is two fold. First, if the wheel is rotating at fewer revolutions per minute than the flow of waters, the blades will not fold in toward the housing because of water pressure holding them outward. The only remedy of this difficulty is to include springs of some sort that would cause the blades to fold in at a selected segment of the rotation, in which case efficiency would be lost. Second, the blades will not enter the upstream waters until the waters have reached near the outward or tip end of the blades due to inward pressure.
Following the issuance of the above patent, a great number of individuals have patented devices that are intended to circumvent the above objections, all of which require complicated moving parts and expensive manufacture, without proven effectiveness.
Among these patents are: U.S. Pat. No. 7,094,017 B2, Aug. 22, 2006; U.S. Pat. No. 6,616,403 B1, Sep. 9, 2003; U.S. Pat. No. 6,499,939 B2, Dec. 31, 2002; U.S. Pat. No. 6,065,935, May 23, 2000; U.S. Pat. No. 5,098,264, Mar. 24, 1992; U.S. Pat. No. 4,776,762, Oct. 11, 1988; U.S. Pat. No. 4,618,312, Oct. 21, 1986; U.S. Pat. No. 4,383,797, May 17, 1983; U.S. Pat. No. 3,692,427, Sep. 19, 1972; U.S. Pat. No. 3,156,278, Nov. 10, 1964; U.S. Pat. No. 1,757,761, May 6, 1930; U.S. Pat. No. 692,714, Feb. 4, 1902; U.S. Pat. No. 226,357, Apr. 6, 1880; U.S. Pat. No. 203,382, May 7, 1878.
U.S. Pat. No. 98,891, Jan. 18, 1870, Current Water Wheel, by A. M. Sory discloses a central drive shaft with blades secured on struts. The device, however, has congestion of blades limiting efficiency as noted above, and there is no provision for the blades to not resist out positioning on the out-of-water arch, and thus, they have limited efficiency.
U.S. Patent Application 20080211232, Sep. 4, 2008, describes a water wheel consisting of foldable vanes designed with hydro foil features included, while diverting water to the vanes for greater power.
U.S. Pat. No. 4,270,056, May 26, 1981, discloses a device with two sets of three bladed assemblies affixed to a drive shaft, and these assemblies are secured on struts extending outward from the drive shaft and are so arranged that each blade does not impede the preceding blade in effective energy transfer. The system requires the positioning of each of the three blade units adjacent to each other, such that one blade of a unit is constantly in an energy transfer stance, while the blade on the other unit is out of the water. There is no provision for blades to effortlessly exit the waters and thus, efficiency is lost in this arrangement. There is a loss of power with the blades adjacent to each other as the waters at the working blade positions are forced to move sideways toward the other blade or outward away from the blades. In the first case, resistance is encountered, while in the second, loss of effective flow is produced.
Applicant has devised an energy efficient system for obtaining power from flowing water that is an improvement over the existing technology.